Lead screw support damping mechanism

Abstract

An improved magnetic read/write head-positioning apparatus including a cantilevered lead screw head carriage-driving mechanism and a damping assembly for damping any transverse motion of the unsupported end of the lead screw. The damping assembly includes a leaf spring having one end affixed to the supporting frame and the other end positioned opposite the unsupported end of the lead screw, and a slider button disposed between the leaf spring and the unsupported lead screw end and carried by the lead screw so as to frictionally engage the leaf spring and cause a force to be exerted on the unsupported lead screw end tending to resist any transverse motion thereof.

What is claimed is: 
     
       1. A magnetic read/write head-positioning apparatus comprising: a frame;   a stepping motor mounted to said frame;   a cantilevered lead screw having one end mounted to the drive shaft of said motor and the other end unsupported, said lead screw being adapted to drive a magnetic read/write head, the unsupported end of said lead screw tending to vibrate in a transverse direction when rotated by said motor due to torsional reaction forces created in moving the head; and   damping assembly means disposed at said unsupported end of said lead screw and including first means carried by said unsupported end and forming a first surface, and resilient means affixed to said frame and forming a second surface, said resilient means being disposed to cause said second surface to engage said first surface with a force directed along the axis of said lead screw, whereby the frictional forces developed between said first and second surfaces due to transverse vibrating motion of said unsupported end tend to resist such motion.   
     
     
       2. A magnetic read/write head-positioning apparatus as recited in claim 1 wherein said resilient means includes an elongated resilient member having one end portion affixed to said frame and another end portion forming said second surface, said second surface being disposed opposite the unsupported end of said lead screw. 
     
     
       3. A magnetic read/write head-positioning apparatus as recited in claim 2 wherein said first means includes a slider button having said first surface formed on one side and means formed on the other side for engaging said unsupported end of said lead screw so that said slider button is caused to follow any transverse motion of said unsupported end. 
     
     
       4. A magnetic read/write head-positioning apparatus as recited in claim 3 wherein said resilient member includes an aperture extending through said second surface and said slider button includes an elongated stub projecting from said one side and extending through said aperture, the transverse dimension of said stub being substantially less than the corresponding dimension of said aperture. 
     
     
       5. A magnetic read/write head-positioning apparatus as recited in claim 4 wherein said unsupported end of said lead screw includes a recess disposed concentric therewith and said slider button includes a second elongated stub projecting from said other side and adapted to be received within said recess. 
     
     
       6. A magnetic read/write head-positioning apparatus as recited in claim 3 wherein said unsupported end of said lead screw includes a recess disposed concentric therewith and wherein said means formed on said other side of said slider button includes an elongated stub projecting from said other side and adapted to be received within said recess. 
     
     
       7. A magnetic read/write head-positioning apparatus as recited in claim 1 wherein said resilient means is a leaf spring capable of exerting a force of between 50 and 400 grams against said unsupported end of said lead screw. 
     
     
       8. A magnetic read/write head-positioning apparatus as recited in claim 1 wherein said first means includes a slider button having a generally hemispherically configured side forming said first surface and means formed on the other side for engaging said unsupported end of said lead screw so that said slider button is caused to follow any transverse motion of said unsupported end. 
     
     
       9. A magnetic read/write head-positioning apparatus as recited in claim 3 wherein said slider button is made of an acetal fluorocarbon material and wherein said resilient member is a metal leaf spring. 
     
     
       10. A magnetic read/write head-positioning apparatus as recited in claim 9 wherein said resilient member is affixed to one end of an elongated carriage guide means which is affixed to said frame.